President Trump, notoriously, tweeted that climate change is a Chinese hoax.

Some 70,000 US citizens in Puerto Rico living along the Guajataca River are in danger as a dam in the vicinity is failing. Built in the 1920s, the earthen dam faces a drainage problem in the midst of the downpours visited on the island, which have abruptly filled it up and put unbearable pressure on the walls.

The failure of this dam underlines that climate change science is absolutely central to good public policy and planning.

As humans put heat trapping gases into the atmosphere, like carbon dioxide, through driving their cars, providing their homes with electricity, and heating or cooling their houses, more of the sun’s heat is trapped on earth rather than radiating off into space. That trapped heat has caused the average temperature of the earth’s surface to rise.

Trapping heat so that it causes the Caribbean to heat up is highly destructive. Warm water powers hurricanes. Hotter water makes them more violent and destructive now.

Warmer water also has more water vapor floating above it. That water turbocharges the rain storms once the hurricane makes landfall.

In Puerto Rico’s case, so much rain fell so heavily and so quickly that it overwhelmed the old earthen dam, which began to fail. It so happens that nearly 70,000 people live down river and are in danger.

People in charge of dams throughout the US need to be made aware of this situation. What is an ordinary load on a dam is about to change, and human-caused climate change will just attribute them to someone else. If you don’t believe in climate change, you cannot justify the expenditure of public funds to reinforce the dam.

If you deny climate change, you will not anticipate heavier rainfall. Your dams will then fail, creating tens of thousands of climate refugees.

Global heating doesn’t cause hurricanes. It simply amplifies them and makes them stronger and makes the rainfall associated with them much heavier.

When you vote for denialist politicians, you are selecting people who make policy. The policy they make will be clueless and will actively endanger the public. Climate change is real. We are causing it by our emissions. If you don’t believe that, you are not a responsible steward of our infrastructure and of our lives.